1. Field of the Invention
The present invention relates generally to an improved data processing system and in particular to a computer implemented method, data processing system and computer program product for recovering resource connections.
2. Description of the Related Art
Enterprise application integration has grown significantly establishing a need to ease the effort required to couple disparate systems together. Industry standards such as Java™ 2 Platform Enterprise Edition Connector Architecture (JCA) have been developed under the Java community process by a group of technology firms to address such needs. Java™ 2 Platform Enterprise Edition or Java EE, as it is now referred, is a set of technologies that enable solutions for the development and deployment, as well as the management of multi-tier, server-centric applications. Java EE adds capabilities to provide a stable, secure, and fast Java platform for enterprise use to reduce the cost and complexity of developing and deploying solutions. The specification for the architecture may be obtained through the Sun Microsystems developer web site. Implementations of the specification may be obtained from various vendors including Sun™, HP™ and IBM®. Java 2 Platform Enterprise Edition Connector Architecture provides a fairly generic way to connect legacy systems with application servers as part of an enterprise application integration solution. Typical solutions are established in a three tier manner comprising a client, a Java 2 Platform Enterprise Edition Connector Architecture application server, and an enterprise information server.
Implementations of Java 2 Platform Enterprise Edition Connector Architecture provide a mechanism to store and retrieve data belonging to an enterprise with the Java 2 Platform Enterprise Edition Connector Architecture environment. The use of Java 2 Platform Enterprise Edition Connector Architecture provides adapters for enterprise connectivity. The use of Java 2 Platform Enterprise Edition Connector Architecture adapters is similar to the use of Java Database Driver Connectivity (JDBC) to connect to and access a database.
Within the scope of the Java 2 Platform Enterprise Edition Connector Architecture is a resource adapter. The resource adapter is specific to an enterprise information system in a manner similar to that of the database connectivity drivers. A resource adapter specific to the resource with which a connection is desired must be available. The resource adapter comes in combination with connectivity management. Connectivity management handles the establishment, pooling, and tear down of connections. Connection management also allows listeners created on a connection to respond to events, particularly when the connection becomes lost or suffers errors. For example, when a network connection is lost, a connection manager may provide a dialog to inform the user of the lost connection and provide an opportunity to re-connect with the network or the application. In another example, an application connection may not be responding and the connection manager may alert the user of the application problem.
Resources of the enterprise information server may be subscribed to by other components or applications. In cases where the connection has been lost, and the resource later becomes available, the subscription has to be restored through subscribing. A subscription may be lost due to a dropped connection to a Java 2 Platform Enterprise Edition Connector Architecture container, such as an application server or an enterprise information server. The subscription information is typically stored in volatile memory, which is lost whenever the server encounters trouble and has to shut down. On restart of the server, the subscriptions must be initialized again by the respective user having the subscription.